Porous tip liquid applicators such as the highly popular “felt tip marker” have enjoyed great popularity through the years. The convenience of utilizing porous tip applicators for liquids such as ink or the like have proven to be particularly advantageous in applying liquids to large areas such as bold lettering or artistic work. While a variety of such porous tip applicators have been provided for various liquids, most generally utilize an elongated body often cylindrical within which a quantity of liquid is contained. At one end of the liquid filled body, a housing often including one or more liquid baffles or other suitable fluid flow control apparatus is secured in communication with the liquid housed in the container. A porous nib often formed of a fabric wick-like material is secured within the housing and is held in communication with the liquid flowing through the baffles. The combined structure provides for the controlled wetting of the nib with the contained liquid allowing the user to write or otherwise transfer the liquid from the felt tip marker to the surface being written upon. For the most part, porous tip writing instruments such as felt tip applicators are provided to the consumer with a quantity of liquid such as ink prefilled within the body of the applicator.
U.S. Pat. No. 2,624,902 issued to Soldner sets forth a FOUNTAIN MARKING DEVICE WITH WORK OPERABLE VALVE which provides an early example of porous tip writing instruments. The device includes a generally cylindrical body having a hollow interior ink reservoir therein. One end of cylindrical body is capped with a closure and vent mechanism while the opposite end of the body is joined to a writing mechanism. The writing mechanism includes a porous material writing nib supported in a sliding attachment to a nib housing. The nib is coupled to a movable valve which is in communication with the liquid such as ink contained within the interior reservoir of the cylindrical body. In operation, the user presses the writing nib against a convenient surface such as the writing material to actuate the flow valve which in turn allows the liquid to flow from the interior reservoir of the cylindrical body to the porous nib thereby wetting the nib and facilitating the transfer or the liquid to the underlying surface. When the pressure is released, the valve closes and further flow of liquid is terminated.
U.S. Pat. No. 2,643,409 issued to Hempel et al. sets forth a FOUNTAIN MARKER which also represents early designs of porous tip writing instruments. The marker includes an elongated cylindrical body having a hollow interior and a closed end. The remaining end of the cylindrical body supports a porous writing nib and a flow valve. The valve is in communication with the interior reservoir of the cylindrical body and is operated to flow liquid to the porous nib whenever the nib is pressed against a writing surface.
U.S. Pat. No. 3,459,484 issued to Abrams sets forth a MARKING DEVICE having an elongated cylindrical body defining an interior liquid reservoir therein. The device includes a liquid fill valve at one end and a writing mechanism at the remaining end. The writing mechanism is pivotally joined to the cylindrical body. A porous writing tip is housed within the writing mechanism and includes a valve in communication with the interior of the cylindrical body.
U.S. Pat. No. 3,640,631 issued to Sotir sets forth a MARKING PEN having a container which in turn houses a liquid reservoir therein together with a marking nib extending from one end of the container. The nib functions for applying fluid such as ink to a surface. The nib is disposed in a cylindrical holder having a center bore therein with at least two shoulders therein. One shoulder forms a valve seat while a valve plunger is secured to the nib and disposed within the bore. The nib and valve plunger cooperate with the valve seat to control the flow of liquid from the interior of the marking applicator to the nib.
In a related art, U.S. Pat. No. 6,250,832 issued to Del Vecchio sets forth a FOUNTAIN PEN WITH DOUBLE RESERVOIR AND PLUNGER FOR FILLING THE PENS BY MEANS OF SUCTION in which a fountain pen includes a large capacity reservoir of ink having a piston-type valve that can be operated to fill the pen by suction. The pen further includes a small supply reservoir adjacent to the writing nib which supplies ink to the nib. A piston valve is provided in order to hermetically close and open a passage between the reservoir and the supply reservoir. The use of two reservoirs provides a reserve reservoir for the pen.
U.S. Pat. No. 5,888,008 issued to Obersteller et al. sets forth a WRITING INSTRUMENTS WITH REFILLABLE RESERVOIR having a supply chamber connected to a reserve chamber by a refilling valve. The refilling valve is actuated by a plunger which in turn is controlled by a push button formed with a self-closing membrane-type valve. The reserve chamber may be filled from a receptacle using a hollow needle. A separating valve at the end of the plunger closes before the refilling valve is opened to ensure that ink will not be forced into the ink flow regulator during the filling process.
While the foregoing described prior art devices have to some extent improved the art of liquid applicators and have in some instances enjoyed commercial success, there remains nonetheless a continuing need in the art for evermore improved application and use specific applicators.